The present invention relates to multiprocessor computer systems and, in particular, to the selection of compatible processors to add to a multiprocessor computer system.
In order to increase the rate at which a computer system can execute instructions, computer manufacturers have adopted various multiprocessor architectures. First used in mainframe and high-end minicomputers, multiprocessor architectures are now commonly available in lower-end computer systems. Manufacturers commonly sell multiprocessor computer systems with fewer processors than the maximum number of processors that can be included in the system. The purchaser of such a system can later expand the multiprocessor computer system to increase its performance by purchasing additional processors and adding those additional processors to the system.
There are many different types of processors, or CPUs, manufactured for use in computer systems. Generally, a given manufacturer will produce different types of CPUs that each have a unique model number. For example, the Intel microprocessors included in personal computer (xe2x80x9cPCxe2x80x9d) systems include the 8086, 80286, 80386, 80386SX, 80486DX, Pentium, and Pentium II processors. Within a given model number of processor, a manufacturer generally produces many different revisions. A new revision may include fixes to problems recognized in older revisions, and may include enhancements to the functionality and performance of the processor.
Additional processors added to a multiprocessor PC system must, in general, be compatible with the processors already included in the system, both in model number and revision number. Processor manufacturers produce lists or tables that include processor compatibility information. Thus, the owner of a multiprocessor PC system that wishes to expand the system by adding an additional CPU must first determine the model and revision numbers of the CPUs currently residing in the PC system and then use the compatibility information provided by the processor manufacturer to select an additional CPU for purchase that is compatible with the CPUs already residing in the system.
The model and revision numbers of a CPU are generally printed or stamped onto the surface of the CPU. However, modern high-speed CPUs are generally enclosed within heat sinks that obscure the model and revision number information. The heat-sink-enclosed CPU is often additionally obscured by a cooling fan mounted on top of the heat sink. The owner of a PC typically determines the model and revision numbers of the CPUs within the computer system by removing the cooling fan and heat sink. This disassembly process is time-consuming and can subject the CPU and circuit board that contains it both to mechanical damage and to electrical damage due to static discharges.
An embodiment of the present invention provides a technique for using processor compatibility information to select a compatible processor for addition to a multiprocessor computer. A multiprocessor computer has at least one current processor in a CPU slot within the computer and at least one additional CPU slot in which a new processor can be added. The additional CPU slot may be empty or may contain a CPU that is to be removed in order to add a new processor. Each processor has a revision number that identifies the revision of the processor. Processors in a multiprocessor computer must generally all have compatible revision numbers. In order to determine a set of compatible revision numbers for a processor to add to multiprocessor computer, the technique executes a software program on the multiprocessor computer to determine the number of current processors in the multiprocessor computer and the revision number of each processor. The technique then executes a software program that compares the revision numbers of the current processors with processor compatibility information to determine the revision numbers of processors that are compatible with all current processors.